EP2316342A1 - Holder system for scanner devices - Google Patents

Abstract

The system has a frame (101) and a drum (102), where support of the drum at a frame allows a rotation of the drum around a rotation symmetric axis. A scanner system is fastened at the drum, which is made of tempered steel. A roller system with rollers (104) is fastened at the frame, and the drum is rotatable around rotation symmetric axis of the drum. The rollers comprises roller surfaces made of hardened steel or ball bearing steel according to DIN EN 10027-1and DIN EN 10027-1.

Description

Technical area

The invention relates to a carrier system for a scanner device, which comprises a frame and a drum, wherein a bearing of the drum on the frame allows rotation of the drum about its axis of rotation symmetrical and wherein on the drum, a scanner system can be fastened.

State of the art

Carrier systems for scanner devices of the above type are known. The scanner system may in particular be an X-ray radiation source and one or more corresponding detectors. The DE 196 29 931 C2 (Siemens) describes, for example, an X-ray computed tomography with an annular gantry, which is rotatably mounted in a frame having rollers for the radial and axial guidance of the gantry. The rollers are offset by 90 ° with respect to each other and run on the outer or side surfaces of rails that surround the gantry at its periphery. The rails are connected to the gantry with the interposition of a rubber layer.

The DE 195 81 512 C2 (Analogic) relates to an X-ray tomography system with a pivotable frame, on which a rotatable drum is arranged. Functional elements of the system (at least the X-ray source) are mounted on the drum. The drum is supported on carriages which comprise tandem rollers which are rotatable about an axis parallel to the axis of rotation of the drum. The running surfaces of the rollers and the carriages are made of elastic material and thus dampen a vibration transmission between the frame and the drum and absorb cyclic temperature changes of the drum. The peripheral, annular member of the drum is by a rolled extrusion of a lightweight material such. As aluminum or a Mg-Al alloy formed. The component forms a uniform, circular band with transversely projecting edge lips, which extend in the radial direction to the outside. In addition to the carriages, the apparatus has at least three pairs of resilient, treaded rollers disposed on the frame for rotation along radial lines. These rollers contact the side edges of the edge lips of the drum and thus guide the latter in the axial direction. The drum is driven by a motor coupled to one of the tandem rollers.

The US 7,010,081 B2 (Philips) shows a CT scanner with a rotating gantry and a fixed gantry, wherein the rotating gantry has a circumferential bearing rail, which for axial and radial bearing inclined tracks having. Conical rollers arranged on the fixed gantry interact in pairs with the raceways of the bearing rail. A drive motor is coupled to one of the rollers for driving the rotating gantry. The roller bearings consist of a metallic core, in particular of steel, and a tire-like polymer coating, in particular of polyurethane, which creates a cushion-like cushioning with simultaneous rigid support.

It has been shown that in such devices, the rotational movement of the gantry is not precisely controlled and that undesired walking movements of the gantry can occur.

The US 5,109,397 (Analogic) shows a computer tomograph with an annular gantry. This is pivotally mounted on a vertical support frame about a horizontal axis, which support frame can be moved linearly along rails relative to a device base. A length-adjustable lever is mounted between the support frame and the gantry and allows pivoting of the gantry. The gantry comprises an outer annular frame and a rotatable inner part, which is mounted on the inside of the frame via rolling bearings.

This solution is structurally complex.

The US 6,188,743 B1 (Analogic) relates to a computed tomography with an annular disc, the peripheral edge is grooved, so that the disc can serve as a pulley, which is driven by a drive motor via a tensioned belt. The disc is mounted on a stationary frame, either in the area of its center of gravity via spacers or peripherally by conventional four-wire bearings. The disc can be made of a lightweight, stiff material such. As aluminum or a magnesium-aluminum alloy and is preferably prepared by precision casting and then cured and finished.

Usual wire bearings have solder joints of the wires, which lead to vibrations at a high rotational speed of the disc. These vibrations cause a background signal in the tomographic images.

Presentation of the invention

The object of the invention is to provide a carrier system belonging to the technical field mentioned at the outset, which allows short examination times, but nevertheless has a cost-effective design.

The solution of the problem is defined by the features of claim 1. According to the invention, the drum consists essentially of tempered steel and on the frame a roller system is fixed with rollers, by means of which the drum is rotatable about the rotational axis of symmetry of the drum. The rollers are made of hardened steel or are at least equipped with treads made of hardened steel.

By producing the tempered steel drum and by the rollers, which at least have treads made of hardened steel, increased rotational speeds of the drum can be achieved without at the same time increasing the vibration of the drum occur. The rotational speeds thus achieved allow short examination times of the scanner device, since vibration-induced background signals are avoided. In addition, an unfavorable noise during the examination is avoided, which would reduce the comfort for the users of the scanner device.

Particularly preferably, the rollers are made of ball bearing steel and are through hardened.

The storage of the drum on a roller system, which allows increased rotational speeds of the drum, is easy and inexpensive to manufacture.

Thus, the inventive carrier system for scanner devices is particularly suitable for applications in which cost a short examination time is desired. This is in addition to the computed tomography in the medical field, especially in baggage handling at airports or customs.

Advantageously, the drum made of tempered steel is produced without joints, in particular seamless rolled or forged. This prevents vibrations that would occur if one of the rollers passes a gap in the drum. This allows a further increase in the rotational speed of the drum without an undesirable increase in vibration.

Preferably, the drum has on the lateral surface over a rail on which run the rollers of the roller system. Advantageously, this rail is made in one piece with the drum of the same material. The rail also preferably has induction hardened running surfaces.

Preferably, the weight of the drum superimposed on several pairs of rollers, which are each mounted on a rocker. In this case, both the axes of rotation of the rockers and the axes of rotation of the rollers are oriented parallel to the axis of rotation of the drum. The axis of rotation of the rockers is preferably located on the mirror-symmetric axis between the two rollers, which runs perpendicular to the connecting line between the two rollers. This storage has the advantage that a self-regulating, even distribution of the weight load of the drum takes place on the mounted on the rocker rollers. In addition, this storage has the advantage that small, temperature-related size and shape changes of the drum are compensated. Since this storage of the drum perpendicular to the rotationally symmetric axis of the drum adapts without giving the drum thereby a translation perpendicular to the rotationally symmetric axis of the drum, and vibrations are suppressed, which at high rotational speed of the drum due to a mismatch of the center of gravity of the drum with the axis of rotation of the Drum can arise.

As an alternative to this storage is also a storage on only two rollers or a storage of the drum on several eccentrically mounted individual rollers conceivable.

Preferably, one or more rollers, on which the weight of the drum is not stored, mounted eccentrically. In the following, an eccentric bearing means an eccentric bearing of the roller axes, wherein the eccentric is set once during assembly and then remains fixed. These rollers have only the function to ensure a backlash-free storage of the drum. Since the rollers are made either entirely of hardened steel or at least a tread of hardened Steel, this is an eccentric storage of the corresponding rollers the best solution.

Alternatively, one or more rollers made of soft material may be used. Such rollers adapt to the size and shape of the drum without having to be eccentrically mounted to it.

Preferably, the drum is held by mounted on the frame guide rollers in the frame. For this purpose, the guide rollers run on both sides of the rail, with their axes are aligned radially to the drum. These guide rollers are made entirely of hardened steel (in particular ball bearing steel) or at least equipped with a tread of hardened steel.

Compared to a likewise conceivable arrangement in which the guide rollers run on the end faces of the drum, the guide roller arrangement of the invention has the advantage that the instruments and components of the scanner device can also be attached to the end faces of the drum.

Compared to another conceivable arrangement of the rollers and the guide rollers on more than one rail on the lateral surface of the drum, this embodiment of the invention further has the advantage that space is saved on the outer surface of the drum and thus the scanner device can be built to save space.

Preferably, the drum is supported without play by the guide rollers are mounted eccentrically on at least one side of the rail. This allows a play-free guidance of the drum and thus a quiet and smooth running with little mechanical stress.

Preferably, the rotational movement of the drum is driven by a drive belt which passes around the drum. This may be any drive belt, for example a V-belt, a flat belt or a toothed belt, act and the drive belt can run in a groove in the lateral surface of the drum or directly on the outer surface of the drum. Preferably, the lateral surface of a drum which is provided with a rail, an integrated side of the rail Pulley on, in particular, the lateral surface is profiled in this area accordingly.

The advantage of the drive via a drive belt is that a good transfer of force takes place on the drum. Alternative drive solutions such as drive via a driving roller or drive roller require non-slip contact between the rail and the driving roller. Such a drive can be achieved only by a special running surface of the driving roller and / or by a strong pressing of the driving roller to the drum. The former would adversely affect the rotational behavior of the drum while the latter would cause high energy loss due to friction.

Preferably, the motor for the drive belt is attached to the frame. This provides the advantage that neither the control nor the power supply for the motor from the frame must be performed on the drum.

Preferably, the drive belt is tensioned by a tension roller, which is attached to the frame. This tension roller has the advantage that the drive belt can be tensioned with a desired force even during operation of the carrier system and that the drive belt can be easily replaced in case of repair.

Preferably, a slip ring is mounted on the outside of the drum through which the required electrical contacts are made to the instruments and components mounted on the drum, with a brush attached to the frame making contact with the slip ring. Alternatively, the required electrical contacts on the drum and the slip ring can be fixedly attached to the frame.

Preferably, the contact with the slip ring on the outside of the drum ensures accurate positioning of the drum.

The advantage of this type of position determination is that, contrary to a determination of the position of the drive motor, it takes place directly on the drum and thus directly determines its position.

Preferably, the instruments and components are secured to holes in the drum.

This type of attachment of instruments and components has the advantage that, according to the invention, a standard version of the carrier system can be used for various scanner devices and that such a scanner device can be expanded with simple means with further or newer instruments and components.

In addition, this type of attachment weight saving, since no heavy spacers are needed.

An alternative way to attach the instruments and components to the drum is to attach a disk to the drum on which the instruments and components are firmly mounted.

From the following detailed description and the totality of the claims, further advantageous embodiments and feature combinations of the invention result.

Brief description of the drawings

Fig. 1

eine Schrägansicht eines erfindungsgemässen Trägersystems für ein Scannergerät,

Fig. 2

eine Frontansicht des erfindungsgemässen Trägersystems, und

Fig. 3

eine weitere Schrägansicht des erfindungsgemässen Trägersystems.

Grundsätzlich sind in den Figuren gleiche Teile mit gleichen Bezugszeichen versehen.The drawings used to explain the embodiment show:

Fig. 1

an oblique view of a carrier system according to the invention for a scanner device,

Fig. 2

a front view of the inventive carrier system, and

Fig. 3

a further perspective view of the inventive carrier system.

Basically, the same parts are provided with the same reference numerals in the figures.

Ways to carry out the invention

The FIG. 1 shows an oblique view of a carrier system according to the invention for scanner devices. The illustrated carrier system comprises a frame 1 which consists of a steel plate and which is mounted upright in a stand (not shown). In this frame 1 there is an opening in which a substantially hollow cylindrical drum 2 with its axis of rotation symmetrical perpendicular to the plane of the steel plate of the frame 1 place. The diameter of this drum 2 is about eight times larger than the length of the drum 2. The drum 2 is forged from heat-treated steel C45 (according to DIN EN 10027-1) without joints. A rail 3 with a rectangular cross-section, which runs in the middle of the lateral surface of the drum 2, surrounds the drum 2 in an annular manner. The rail 3 is forged together with the drum 2 in one piece. The three free faces of the rail are induction hardened (58 (0 / + 4) HRC). The drum 2 is mounted in the frame 1 so that the annular rail 3 and the frame 1 lie substantially in one plane. The annular rail 3 supports it on the outside (ie, the side facing the frame 1) at three points on lower rollers 4 and an upper roller 5. These lower and upper rollers 4, 5 are either entirely made of through-hardened (59 (0 / + 4) HRC) ball bearing steel (100Cr6 according to DIN EN 10027-1) or they have running surfaces made of hardened (59 (0 / + 4) HRC) ball bearing steel (100Cr6 according to DIN EN 10027-1). The lower rollers 4 and the upper roller 5 are mounted on the frame 1. In a polar coordinate system in which the angular coordinate at the uppermost point in the opening of the frame 1 starts at 0 degrees and then rotates clockwise in the plane of the frame 1, one pair of the lower rollers 4 is at 135 ° and 225 ° at the frame 1 mounted. Since the frame 1 is vertical, the weight of the drum 2 rests on these two pairs of lower rollers 4. Both pairs of the lower rollers 4 are parallel to the axis of the lower rollers 4 parallel to the axis of rotation of the drum 2 on a rocker 6 in a suitable Recess of the opening of the frame 1 mounted (see FIG. 3 ; In the view of FIG. 1 These rockers are 6 on the back of the frame 1). The rockers 6 are tiltable about an axis which is parallel to the axis of rotation of the drum 2. The axis of the rockers 6 lies in the mirror-symmetrical plane Rockers 6, which is perpendicular to the connecting line between the two axes of the lower rollers 4. The rocking movement made possible by the rockers 6 ensures that the weight of the drum 2 is evenly distributed over all lower rollers 4.

At 0 ° of the angular coordinate of the mentioned polar coordinate system, the upper roller 5 is mounted eccentrically and clamps the drum 2 between them and the lower rollers 4. Together prevent the lower and upper rollers 4, 5 a displacement of the drum 2 in the plane of the frame 1 and allow simultaneous rotation of the drum 2 about its axis of rotation symmetrical.

Thus, the rail 3 of the drum 2 and the frame 1 remain in one plane, guide rollers 7 are mounted on the frame 1, which consist of through hardened (59 (0 / + 4) HRC) ball bearing steel (100Cr6 according to DIN EN 10027-1) or which at least running surfaces made of hardened ball bearing steel (100Cr6 according to DIN EN 10027-1). These guide rollers 7 are each arranged in pairs, wherein per pair of a guide roller 7 on one side of the surface of the frame 1 (and the rail 3) and the other guide roller 7 on the other side of the frame 1 (and the rail 3) attached is and runs on the respective side surface of the rail 3. Overall, three pairs of guide rollers 7 are arranged symmetrically at the angular coordinates 45 °, 180 ° and 315 ° about the drum 2 (see FIG. 2 ). The axes of the guide rollers 7 point radially away from the rotationally symmetric axis of the drum 2. On the side facing away from the rotationally symmetrical axis of the drum 2 side of the guide rollers 7, the axes of the guide rollers 7 are held by guide roller holders 8. These guide roller holder 8 are fixedly mounted on the frame 1. At least on one side of the frame 1, the guide rollers 7 are mounted eccentrically, whereby the drum 2 is mounted without clearance in the frame 1.

On the rocker 6 opposite side of the frame 1, a belt 9 is arranged, which runs in a groove 2 incorporated in the drum. The V-belt 9 is driven by a drive roller 11. It revolves around the drum 2 and the drive roller 11 without crossing over. The lower part of the V-belt 9 is pushed up immediately after the drive roller 11 by a tension roller 12 and so stretched. Both the drive roller 11, and the tension roller 12 are mounted on the frame 1. The axis of Drive roller passes through the frame 1 and is driven on the other side of the frame 1 by a motor 13.

On the drum 2, on the side facing away from the frame 1 side of the V-belt 9, a slip ring 14 attached to a dedicated interface, which (not shown) via a brush attached to the frame 1, the electrical contacts for the instruments and components which on the drum 2 are attached (not shown), manufactures. This contact with the slip ring 14 also allows an accurate determination of the position of the drum 2. Corresponding slip ring systems are known and are offered for example by the company Schleifring, Fürstenfeldbruck, Germany.

The FIG. 2 shows a front view of the inventive carrier system for scanner devices. Well visible here is the symmetrical arrangement of the lower rollers 4 at the angular coordinates 135 ° and 225 ° and the upper roller 5 at the angle coordinate 0 ° and the guide rollers 7 and the guide roller holder 8 at the angular coordinates 45 °, 180 ° and 315 ° to the Drum 2 around.

The FIG. 3 shows an oblique view of the inventive carrier system for scanner devices. In contrast to FIG. 1 and 2 This view shows the back of the carrier system.

The two rockers 6 are mounted on the frame 1 and each hold two lower rollers 4. (The lower rollers 4 are visible only from the other side, see FIG. 1 and 2 .)

A housing 15 is fixed to the frame 1 and houses the eccentrically mounted upper roller 5. (The upper roller 5 is visible only from the other side, see FIG. 1 and 2 .)

On the side of the drum 2 shown here is a hole pattern (not shown) which allows the attachment of the instruments and components (not shown) to the drum 2.

The invention is not limited to the illustrated embodiment. Depending on the specific application, for example, the edge of the drum 2 between the attached to the drum 2 instruments and components have recesses, whereby the total mass of the drum 2 is reduced. This allows the use of a less powerful motor 13 and a correspondingly less powerful V-belt.

Furthermore, for example, the V-belt 9 may be replaced by a toothed belt or other types of drive belt.

Depending on the specific application, for example, the arrangement of the drive belt, the slip ring 14 and the holes for attachment of instruments and components on the drum 2 can be varied. In this case, both drive belt, slip ring 14 and holes can be placed on one or the other side of the frame 1 on the drum 2.

Depending on the application of the carrier system, the arrangement of the rollers 4, 5 can be changed. In addition, more than one roller 5 can be used. Accordingly, depending on the need, the positions of the guide rollers 7 can be varied.

In summary, it should be noted that a carrier system for scanner devices is provided by the invention, which allows short examination times, but still constructed inexpensively.

Claims (13)

Carrier system for a scanner device, which comprises a frame (1) and a drum (2), wherein a bearing of the drum (2) on the frame (1) allows a rotation of the drum (2) about its axis of rotation symmetry and wherein on the drum ( 2) a scanner system is fastened, characterized in that the drum (2) consists essentially of tempered steel and in that on the frame (1) a roller system with rollers (4, 5) is fixed, by means of which the drum (2) to the Rotation symmetry axis of the drum (2) is rotatable, wherein the rollers (4, 5) made of hardened steel or are equipped at least with running surfaces made of hardened steel. Carrier system according to claim 1, characterized in that the drum (2) produced without joints, in particular forged or rolled, is. Support system according to claim 1 or 2, characterized in that the drum (2) on the lateral surface via a rail (3), on which run the rollers (4, 5) of the roller system. Support system according to one of claims 1-3, characterized in that the weight of the drum (2) on a plurality of roller pairs (4) superimposed, which are each mounted on a rocker (6). Support system according to one of claims 1 - 4, characterized in that one or more further rollers (5) on which the weight of the drum (2) does not support, are mounted eccentrically. Support system according to one of claims 1 to 5, characterized in that the drum (2) is mounted on the frame (1) by guide rollers (7) in the frame (1). is held by the guide rollers (7) running on both sides of the rail (3) and by the axes of the guide rollers (7) are aligned radially to the drum (2), wherein the guide rollers (7) are made entirely of hardened steel or at least equipped with a tread of hardened steel. Carrier system according to claim 6, characterized in that the drum (2) is mounted without play by the guide rollers (7) are mounted eccentrically on at least one side of the rail (3). Carrier system according to one of claims 1-7, characterized in that the rotational movement of the drum (2) is driven by a drive belt (9) running around the drum (2). Support system according to one of claims 1 - 8, characterized in that the motor (13) for the drive belt (9) on the frame (1) is attached. Support system according to one of claims 1 - 9, characterized in that the drive belt (9) by a tension roller (12) is tensioned. Carrier system according to one of claims 1-10, characterized in that a slip ring (14) on the outside of the drum (2) produces the required electrical contacts to the instruments which are fixed to the drum (2). Support system according to one of claims 1 - 11, characterized in that by a contact to the slip ring (14) on the outside of the drum (2), the exact position determination of the drum (2) is ensured. A support system according to any one of claims 1-12, characterized in that the radiation source and the detector or detectors are fixed to holes in the drum (2).

Images